1. Field of the Invention
The present invention relates to an information input device used for inputting information into various types of electronic devices such as computers, and particularly to a keyboard having keys serving as operation members.
2. Description of the Related Art
Generally, a keyboard having keys as operation members is widely used and known as an information input device used for inputting information into a computer.
It is well known that the keyboard has a tilt mechanism capable of tilting the top face (key-arrayed surface) of the keyboard so that a user can readily input information. Generally, a tilt leg foldable to be held on the back face of the keyboard is employed in the tilt mechanism (see Japanese Patent Application Publication No. 59-072538, Japanese Utility Model Application Publication No. 61-189320 and Japanese Patent Application Publication No. 62-019925, for example).
However, the conventional tilt mechanism employing a foldable tilt leg has the following problems.
(1) The tilt leg held on the back face of the keyboard when not in use needs to be pulled out so as to tilt the keyboard, and needs to be folded so as to release the tilted state of the keyboard. Therefore, its operability is poor.
(2) The tilt leg has a pin serving as a shaft for realizing the folding structure. The pin has to bear a load in the state when the tilt leg is pulled out. Also, the load focuses on the tilt leg standing on a desk. Accordingly, (a) if a user roughly handles the keyboard or leaves something on the keyboard thereby imposing a heavy load thereon, the tilt leg might be accidentally folded, resulting in unintended data input; (b) the pin might accidentally come off the keyboard; and (c) the pin or a hole of the keyboard into which the pin is inserted might be accidentally damaged.
(3) The tilt leg can only shift to a single pulled-out state, i.e. only one tilt angle is available in the conventional tilt mechanism and therefore, various tilt angles desired by individual users cannot be achieved in this mechanism.